4 Seasons in a Year

Why does the Earth have Seasons?

At the moment, in Ireland anyway the weather is crazy. It seems like we are having 4 seasons in one day. ThisÂ I cannot explain. What I can explain however is why the earth has 4 season in one year.

Earths axis is tilted by 23 degrees, it is this tilt that gives earths its distinct seasons. As the earth moves around the sun this tilt causes the earth to wobble.

The seasons come about when different parts of the earth are angled towards or away from the sun, getting more or less heat. As you can see in the image above, when it is summer in the northern hemisphere it is winter in the southern hemisphere. This is because the northern hemisphere is tilted towards the sun as the year progresses this tilt moves the northern hemisphere away from the sun and into winter.

Why is Earth tilted?

No one really knows, but the most likely reason is that a very young earth crashed into another large body in the early solar system. A big enough impact would be able to knock earth of a central axis and created our tilt. The residue left overÂ from this impactÂ may have even helped form our moon.

It is amazing to think that an impact billions of years ago not only helped create an environment that has giving us a summer,winter,autumn and spring but also helped create out closest companion the moon and with it the tides of the sea and wonders like solar eclipses.